We are documenting the remarkable capacity of the stomach in rhesus monkeys to empty calories in a regulated fashion into the small intestine. We have demonstrated that regardless of the concentration, volume, or chemical nature of liquid nutrients within it the stomach will deliver calories to the duodenum at a constant rate. We are presently investigating the duration of this phenomenon, its relationship to calories in the duodenum and its influence in feeding behavior. It is apparent that gastric distention is an important influence on short term "meal time" satiety with its remarkable preabsorptive feature of caloric control as the outcome of a physiological system of gastro-enteric coordination. It is the examination of the elements of this system (intestinal hormones and central neural connections) and the documentation of their quantitative relationships to feeding that represent the foci of our present work.